Massive coral bleaching spreads globally and deepens in reefs: Environment: Nature World News

Scientists warned that widespread coral bleaching, first discovered by US officials last month, is spreading and worsening in reefs around the world.

Coral damage

The US National Oceanic and Atmospheric Administration (NOAA) said coral bleaching has been observed in 62 countries and territories since February 2023 at record ocean temperatures. This is an increase of nine compared to the warning in April.

Derek Manzello, the coordinator of NOAA’s Coral Reef Watch program, emphasized that the impact of this event continues to increase.

“This is not something that would happen without climate change,” he added.

According to Manzello, new coral damage has been observed in India, Sri Lanka and the Chagos Islands in the Indian Ocean since NOAA issued its warning on April 15.

Corals that experience extreme or prolonged heat stress eventually die, but can revive if temperatures drop and other stressors such as pollution and overfishing are reduced.

The effects of coral bleaching are extensive, impacting not only the well-being of the oceans, but also local economies, human livelihoods and food security.

There have been three previous cases of mass coral bleaching in the world between 1998 and 2017, making the current one the fourth.

According to NOAA, a record 60.5 percent of the world’s reefs have experienced bleach-like heat in the past 12 months.

The previous global bleaching event, which occurred between 2014 and 2017, still currently holds the record for the most cumulative impact.

As the oceans continue to warm this summer, Manzello warned that bleaching could occur at reefs across Asia, as well as off the coasts of Mexico, Belize, the Caribbean and Florida.

So far, the bleaching has affected the Great Barrier Reef near Australia, as well as coral in Thailand.

In Singapore, 20 percent of corals at Kusu Island showed stress or partial bleaching, according to Dr. Jani Tanzil, director of the St. John’s Island National Marine Laboratory Facility (SJINML).

The Sisters’ Islands, part of Singapore’s only marine park, have also noticed mild bleaching.

Also read: El Niño and Coral Bleaching: longest event ever, lasting longer

Heat stress

According to Karin Gleason, chief of the monitoring division at NOAA’s National Centers for Environmental Information, there is a 100 percent chance that 2024 will be among the top five warmest years on record and a 61 percent chance that it will end up being the warmest year on record. . file.

The world’s oceans experienced their warmest temperatures in April last month, breaking a record that had been set every month for the previous thirteen months.

In the Atlantic Ocean, the accumulation of heat stress is incredibly rare and severe.

It may take some time before we understand the effects of coral bleaching. In the Caribbean, for example, coral can withstand initial heat stress before succumbing to “disease outbreaks or accumulations of coral predators.”

Due to a complex combination of El Niño weather patterns and climate change, last year was the hottest year on record.

This year, “I hope that… we will see the percentage of reef areas affected start to decrease,” Manzello added, as the cooling La Niña pattern takes effect between now and fall.

Related article: Coral bleaching: Reefs adapted to warm waters are equally threatened by climate change

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